The present invention relates generally to oscillators for, in response to an input signal, generating a periodically varying electrical output within a frequency range such as a millimeter wave and a submillimeter wave.
A Gunn diode oscillator having a waveguide construction is a known solid-state oscillator for generating an output existing within the millimeter or submillimeter band. However, such a diode oscillator requires a larged-sized resonator in comparison with wavelengths and is difficult to manufacture with the required accuracy. In order to avoid this problem a Fabry-Perot type resonator has been proposed whereby it is possible to realize a large-sized resonator in comparison with wavelengths. However, a solid-state oscillator with the Fabry-Perot type resonator has disadvantages in terms of mechanical strength and heat radiation and hence is not yet in practical use. Thus, a further improvement would be required from the veiwpoint of practical use.